2008 Toyota Prius Owners Manual - Page 110

1-6. Refueling Closing the fuel tank cap After refueling, turn the fuel tank cap clockwise until you hear a click. The cap will revolve slightly in the opposite direction once released. 1 Before driving n Fuel types Use unleaded gasoline. (87 Octane Rating [Research Octane Number 91] or higher) n Fuel tank capacity Approximately 11.9 gal. (45 L, 9.9 Imp. gal.) 79 PRIUS_U_(L/O_0802)